Multiphosphorylated proteins are typically non-enzymic and occur in diverse forms of life, including mammals. They can bind biologically important metals such as Fe, Ca, and Mg, but limited biochemical insight into such complexes makes their physiological significance elusive. Such insight is expected from the proposed study of the metal complexes of a model phosphoprotein, in terms of 1) protein structural requirements and reactive consequences of complex formation, 2) binding strength, 3) binding site multiplicity and heterogeneity, and 4) the dynamics of metal ion competition, exchange, and transfer. The egg protein phosvitin, and specifically modifed or fragmented phosvitin derivatives will be used. The chemical description of this protein is extensive and its interactions with metals, particularly iron, have already raised a number of functional working hypotheses rooted in the metal ion-promoted intramolecular shift of phosphate between ester and amide linkages, or the iron-dependent oxidative removal of protein-bound phosphate as a product of high phosphorylating potential. Also, a variety of phosvitin species is at hand, permitting a search for evolutionarily conserved features of potential biological importance. The methods to be used include physical and organic chemical techniques of protein chemistry and inorganic biochemistry. On the long term, the results are expected to contribute to the understanding of molecular mechanisms by which multiphosphorylated proteins and metals may be involved in the dynamics of supramolecular structures such as skin, bone, teeth, and--at the subcellular level--egg yolk particles, membranes and perhaps even ribosomal and chromosomal structures, all of which are associated with multiple phosphorylated protein sites and metals, at least at certain times of their developmental or metabolic functional states. The results may be of use also in human nutrition because of the potential of such natural metal--and particularly iron--carriers as delivery vehicles in cases of dietary metal deficiency.